EARLY DETECTION OF PERITONITIS IN CONTINUOUS AMBULATORY PERITONEAL-DIALYSIS PATIENTS BY USE OF CHEMILUMINESCENCE - EVALUATION OF DIAGNOSTIC-ACCURACY BY RECEIVER-OPERATING CHARACTERISTIC CURVE ANALYSIS

Continuous ambulatory peritoneal dialysis (CAPD) is now a widely accep ted treatment for end-stage renal disease. However, the high incidence of peritonitis is a major complication of CAPD. Polymorphonuclear leu kocytes (PMNs) play a major role in antimicrobial response of the host . During phagocytosis, the PMNs undergo a striking increase in oxidati ve metabolism, known as the respiratory burst, and emit light as chemi luminescence (CL). CL is thus a sensitive measure of PMN oxidative pot ential and correlates well with antimicrobial activity. In view of the observation of increased susceptibility to infection in CAPD patients , we have studied lucigenin- and luminol-enhanced CL in peritoneal flu ids of these patients and assessed the diagnostic accuracy of these te sts by ROC curve analysis. ROC curves showed diagnostic accuracies for both tests that were superior to counts of PMNs in the dialysis fluid (P <0.001). At selected cutoff values of 150 000 cpm/vial for lucigen in CL and 600 000 cpm/vial for luminol CL, sensitivities were 100%. Sp ecificities for lucigenin and luminol CL. were 89% and 80%, respective ly. Our results suggest that CL measurements can be used as an early m arker for the presence of infection in CAPD patients.